auxv: require the target to be tracable (or yourself)

same as for environ, except that we didn't do any checks to
prevent access after suid execve

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index fc471b8766d1..e94b58b496f1 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -281,9 +281,9 @@ out:
 
 static int proc_pid_auxv(struct task_struct *task, char *buffer)
 {
-        int res = 0;
-        struct mm_struct *mm = get_task_mm(task);
-        if (mm) {
+        struct mm_struct *mm = mm_for_maps(task);
+        int res = PTR_ERR(mm);
+        if (mm && !IS_ERR(mm)) {
                 unsigned int nwords = 0;
                 do {
                         nwords += 2;